﻿#include "tree.h"

#define		RB_RED       0
#define		RB_BLACK     1

#define rb_parent(r)   (( rb_node *)((r)->rb_parent_color & ~3))
#define rb_color(r)   ((r)->rb_parent_color & 1)
#define rb_is_red(r)   (!rb_color(r))
#define rb_is_black(r) rb_color(r)
#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)
#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)

static  void rb_set_parent(rb_node *rb, rb_node *p)
{
    rb->rb_parent_color = (rb->rb_parent_color & 3) | (size_t)p;
}

static  void rb_set_color(rb_node *rb, int color)
{
    rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
}

#define rb_entry(ptr, type, member) container_of(ptr, type, member)

#define RB_EMPTY_ROOT(root)        ((root)->rb_node == NULL)
#define RB_EMPTY_NODE(node)        (rb_parent(node) == node)
#define RB_CLEAR_NODE(node)        (rb_set_parent(node, node))

void rb_insert_color(rb_node *node, rb_root *root);
void rb_erase(rb_node *node, rb_root *root);

typedef void(*rb_augment_f)(rb_node *node, void *data);

void rb_augment_insert(rb_node *node, rb_augment_f func, void *data);
rb_node *rb_augment_erase_begin(rb_node *node);
void rb_augment_erase_end(rb_node *node, rb_augment_f func, void *data);

/* Find logical next and previous nodes in a tree */
rb_node *rb_next(rb_node *);
rb_node *rb_prev(rb_node *node);
rb_node *rb_first(rb_root *);
rb_node *rb_last(rb_root *);

/* Fast replacement of a single node without remove/rebalance/add/rebalance */
void rb_replace_node(rb_node *victim, rb_node *new, rb_root *root);

static  void rb_link_node(rb_node * node, rb_node * parent, rb_node ** rb_link)
{
    node->rb_parent_color = (size_t)parent;
    node->rb_left = node->rb_right = NULL;

    *rb_link = node;
}

static void __rb_rotate_left(rb_node *node, rb_root *root)
{
    rb_node *right = node->rb_right;
    rb_node *parent = rb_parent(node);

    if ((node->rb_right = right->rb_left))
        rb_set_parent(right->rb_left, node);
    right->rb_left = node;

    rb_set_parent(right, parent);

    if (parent)
    {
        if (node == parent->rb_left)
            parent->rb_left = right;
        else
            parent->rb_right = right;
    }
    else
        root->rb_node = right;
    rb_set_parent(node, right);
}

static void __rb_rotate_right(rb_node *node, rb_root *root)
{
    rb_node *left = node->rb_left;
    rb_node *parent = rb_parent(node);

    if ((node->rb_left = left->rb_right))
        rb_set_parent(left->rb_right, node);
    left->rb_right = node;

    rb_set_parent(left, parent);

    if (parent)
    {
        if (node == parent->rb_right)
            parent->rb_right = left;
        else
            parent->rb_left = left;
    }
    else
        root->rb_node = left;
    rb_set_parent(node, left);
}

void rb_insert_color(rb_node *node, rb_root *root)
{
    rb_node *parent, *gparent;

    while ((parent = rb_parent(node)) && rb_is_red(parent))
    {
        gparent = rb_parent(parent);

        if (parent == gparent->rb_left)
        {
            {
                register rb_node *uncle = gparent->rb_right;
                if (uncle && rb_is_red(uncle))
                {
                    rb_set_black(uncle);
                    rb_set_black(parent);
                    rb_set_red(gparent);
                    node = gparent;
                    continue;
                }
            }

            if (parent->rb_right == node)
            {
                register rb_node *tmp;
                __rb_rotate_left(parent, root);
                tmp = parent;
                parent = node;
                node = tmp;
            }

            rb_set_black(parent);
            rb_set_red(gparent);
            __rb_rotate_right(gparent, root);
        }
        else {
            {
                register rb_node *uncle = gparent->rb_left;
                if (uncle && rb_is_red(uncle))
                {
                    rb_set_black(uncle);
                    rb_set_black(parent);
                    rb_set_red(gparent);
                    node = gparent;
                    continue;
                }
            }

            if (parent->rb_left == node)
            {
                register rb_node *tmp;
                __rb_rotate_right(parent, root);
                tmp = parent;
                parent = node;
                node = tmp;
            }

            rb_set_black(parent);
            rb_set_red(gparent);
            __rb_rotate_left(gparent, root);
        }
    }

    rb_set_black(root->rb_node);
}

static void __rb_erase_color(rb_node *node, rb_node *parent, rb_root *root)
{
    rb_node *other;

    while ((!node || rb_is_black(node)) && node != root->rb_node)
    {
        if (parent->rb_left == node)
        {
            other = parent->rb_right;
            if (rb_is_red(other))
            {
                rb_set_black(other);
                rb_set_red(parent);
                __rb_rotate_left(parent, root);
                other = parent->rb_right;
            }
            if ((!other->rb_left || rb_is_black(other->rb_left)) &&
                (!other->rb_right || rb_is_black(other->rb_right)))
            {
                rb_set_red(other);
                node = parent;
                parent = rb_parent(node);
            }
            else
            {
                if (!other->rb_right || rb_is_black(other->rb_right))
                {
                    rb_set_black(other->rb_left);
                    rb_set_red(other);
                    __rb_rotate_right(other, root);
                    other = parent->rb_right;
                }
                rb_set_color(other, rb_color(parent));
                rb_set_black(parent);
                rb_set_black(other->rb_right);
                __rb_rotate_left(parent, root);
                node = root->rb_node;
                break;
            }
        }
        else
        {
            other = parent->rb_left;
            if (rb_is_red(other))
            {
                rb_set_black(other);
                rb_set_red(parent);
                __rb_rotate_right(parent, root);
                other = parent->rb_left;
            }
            if ((!other->rb_left || rb_is_black(other->rb_left)) &&
                (!other->rb_right || rb_is_black(other->rb_right)))
            {
                rb_set_red(other);
                node = parent;
                parent = rb_parent(node);
            }
            else
            {
                if (!other->rb_left || rb_is_black(other->rb_left))
                {
                    rb_set_black(other->rb_right);
                    rb_set_red(other);
                    __rb_rotate_left(other, root);
                    other = parent->rb_left;
                }
                rb_set_color(other, rb_color(parent));
                rb_set_black(parent);
                rb_set_black(other->rb_left);
                __rb_rotate_right(parent, root);
                node = root->rb_node;
                break;
            }
        }
    }
    if (node)
        rb_set_black(node);
}

void rb_erase(rb_node *node, rb_root *root)
{
    rb_node *child, *parent;
    int color;

    if (!node->rb_left)
        child = node->rb_right;
    else if (!node->rb_right)
        child = node->rb_left;
    else
    {
        rb_node *old = node, *left;

        node = node->rb_right;
        while ((left = node->rb_left) != NULL)
            node = left;

        if (rb_parent(old)) {
            if (rb_parent(old)->rb_left == old)
                rb_parent(old)->rb_left = node;
            else
                rb_parent(old)->rb_right = node;
        }
        else
            root->rb_node = node;

        child = node->rb_right;
        parent = rb_parent(node);
        color = rb_color(node);

        if (parent == old) {
            parent = node;
        }
        else {
            if (child)
                rb_set_parent(child, parent);
            parent->rb_left = child;

            node->rb_right = old->rb_right;
            rb_set_parent(old->rb_right, node);
        }

        node->rb_parent_color = old->rb_parent_color;
        node->rb_left = old->rb_left;
        rb_set_parent(old->rb_left, node);
        goto color;
    }

    parent = rb_parent(node);
    color = rb_color(node);

    if (child)
        rb_set_parent(child, parent);
    if (parent)
    {
        if (parent->rb_left == node)
            parent->rb_left = child;
        else
            parent->rb_right = child;
    }
    else
        root->rb_node = child;

color:
    if (color == RB_BLACK)
        __rb_erase_color(child, parent, root);
}

void rb_augment_path(rb_node *node, rb_augment_f func, void *data)
{
    rb_node *parent;

up:
    func(node, data);
    parent = rb_parent(node);
    if (!parent)
        return;

    if (node == parent->rb_left && parent->rb_right)
        func(parent->rb_right, data);
    else if (parent->rb_left)
        func(parent->rb_left, data);

    node = parent;
    goto up;
}

void rb_augment_insert(rb_node *node, rb_augment_f func, void *data)
{
    if (node->rb_left)
        node = node->rb_left;
    else if (node->rb_right)
        node = node->rb_right;

    rb_augment_path(node, func, data);
}

rb_node *rb_augment_erase_begin(rb_node *node)
{
    rb_node *deepest;

    if (!node->rb_right && !node->rb_left)
        deepest = rb_parent(node);
    else if (!node->rb_right)
        deepest = node->rb_left;
    else if (!node->rb_left)
        deepest = node->rb_right;
    else {
        deepest = rb_next(node);
        if (deepest->rb_right)
            deepest = deepest->rb_right;
        else if (rb_parent(deepest) != node)
            deepest = rb_parent(deepest);
    }

    return deepest;
}

void rb_augment_erase_end(rb_node *node, rb_augment_f func, void *data)
{
    if (node)
        rb_augment_path(node, func, data);
}

rb_node *rb_first(rb_root *root)
{
    rb_node  *n;

    n = root->rb_node;
    if (!n)
        return NULL;
    while (n->rb_left)
        n = n->rb_left;
    return n;
}

rb_node *rb_last(rb_root *root)
{
    rb_node  *n;

    n = root->rb_node;
    if (!n)
        return NULL;
    while (n->rb_right)
        n = n->rb_right;
    return n;
}

rb_node *rb_next(rb_node *node)
{
    rb_node *parent;

    if (rb_parent(node) == node)
        return NULL;

    if (node->rb_right) {
        node = node->rb_right;
        while (node->rb_left)
            node = node->rb_left;
        return (struct rb_node *)node;
    }

    while ((parent = rb_parent(node)) && node == parent->rb_right)
        node = parent;

    return parent;
}

rb_node *rb_prev(rb_node *node)
{
    rb_node *parent;

    if (rb_parent(node) == node)
        return NULL;

    if (node->rb_left) {
        node = node->rb_left;
        while (node->rb_right)
            node = node->rb_right;
        return (struct rb_node *)node;
    }

    while ((parent = rb_parent(node)) && node == parent->rb_left)
        node = parent;

    return parent;
}

void rb_replace_node(rb_node *victim, rb_node *new, rb_root *root)
{
    rb_node *parent = rb_parent(victim);

    if (parent) {
        if (victim == parent->rb_left)
            parent->rb_left = new;
        else
            parent->rb_right = new;
    }
    else {
        root->rb_node = new;
    }
    if (victim->rb_left)
        rb_set_parent(victim->rb_left, new);
    if (victim->rb_right)
        rb_set_parent(victim->rb_right, new);

    *new = *victim;
}

rb_root *rb_new() {
    rb_root* new = (rb_root *)malloc(sizeof(rb_root));
    if (new) {
        memset(new, 0, sizeof(rb_root));
        return new;
    }
    return NULL;
}

int rb_insert(key_t key, data_t data, rb_root *root) {
    rb_node **new = &(root->rb_node);
    rb_node  *parent = 0;
    rb_node  *rbt = (rb_node *)malloc(sizeof(rb_node));
    memset(rbt, 0, sizeof(rb_node));
    rbt->data = data;
    rbt->key = key;
    /* Figure out where to put new node */
    while (*new)
    {
        rb_node *this = *new;

        int result = rbt->key - this->key;

        parent = *new;

        if (result < 0)
            new = &((*new)->rb_left);
        else if (result > 0)
            new = &((*new)->rb_right);
        else
            return 0; // the key is already exists
    }

    /* Add new node and rebalance tree. */
    rb_link_node(rbt, parent, new);
    rb_insert_color(rbt, root);
    return 1;
}

rb_node *rb_search(key_t key, rb_root *root) {
    rb_node *node = root->rb_node;

    while (node)
    {
        rb_node *this = node;

        int result = key - this->key;

        if (result < 0)
            node = node->rb_left;
        else if (result > 0)
            node = node->rb_right;
        else
            return this;
    }
    return NULL;
}

void rb_delete(key_t key, rb_root*root) {
    struct rb_node *find = rb_search(key, root);
    if (!find)
        return;
    rb_erase(find, root);
    free(find);
    return;
}

void rb_free(rb_root*root) {
    if (root->rb_node)
        rb_delete(root, root->rb_node);
    free(root);
}

void rb_foreach_c(rb_node *node, TreeVisitFunc visitfunc) {
    if (node != NULL) {
        rb_foreach_c(node->rb_left, visitfunc);
        visitfunc(node->data);
        rb_foreach_c(node->rb_right, visitfunc);
    }
}
void rb_foreach(rb_root *root, TreeVisitFunc visitfunc) {
    rb_foreach_c(root->rb_node, visitfunc);
}

//查找最小最小结点
rb_node *rb_minkey(rb_root *root) {
    rb_node *x = root->rb_node;
    rb_node *p = NULL;
    while (x != NULL) {
        p = x;
        x = x->rb_left;
    }
    return p;
}

//查找最大结点
rb_node *rb_maxkey(rb_root *root) {
    rb_node *x = root;
    rb_node *p = NULL;
    while (x != NULL) {
        p = x;
        x = x->rb_right;
    }
    return p;
}
